253 research outputs found
Varying Levels of the Dian Lakes and the Dian Lakes Culture
Historical records state that the Dian kingdom was based on thousands of square li of rich flat land around Dianchi Lake. However, through use of a digital elevation model of the area, it is found that this area was about 800 li2—substantially less. Even if the other major Dian Lakes—Fuxian, Xinyung and Qi Lu—are included, the area increases to only about 1,000 li2. In the process of checking the area stated in the historical records, some issues warranting further exploration have been brought to light: the possibility of a human role in the recurring floods of Dianchi Lake from the 13th c CE; the idea that the settlement site found near Wangjiadun village and tentatively assigned to the early Bronze Age, could be dated to at least 4,500 BP, well before; and that the Shizhaishan and Lijiashan elite cemeteries may have looked out over water to their east. The seemingly limited area of fertile land also suggests that other sources of wealth such as trade and minerals played a greater role, and that the population was relatively small. This calls into question the nature of the socio-political structure within the Dian lakes culture
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Ozone Inhalation Attenuated the Effects of Budesonide on Aspergillus fumigatus-Induced Airway Inflammation and Hyperreactivity in Mice.
Inhaled glucocorticoids form the mainstay of asthma treatment because of their anti-inflammatory effects in the lung. Exposure to the air pollutant ozone (O3) exacerbates chronic airways disease. We and others showed that presence of the epithelial-derived surfactant protein-D (SP-D) is important in immunoprotection against inflammatory changes including those induced by O3 inhalation in the airways. SP-D synthesis requires glucocorticoids. We hypothesized here that O3 exposure impairs glucocorticoid responsiveness (including SP-D production) in allergic airway inflammation. The effects of O3 inhalation and glucocorticoid treatment were studied in a mouse model of allergic asthma induced by sensitization and challenge with Aspergillus fumigatus (Af) in vivo. The role of O3 and glucocorticoids in regulation of SP-D expression was investigated in A549 and primary human type II alveolar epithelial cells in vitro. Budesonide inhibited airway hyperreactivity, eosinophil counts in the lung and bronchoalveolar lavage (BAL) and CCL11, IL-13, and IL-23p19 release in the BAL of mice sensitized and challenged with Af (p < 0.05). The inhibitory effects of budesonide were attenuated on inflammatory changes and were completely abolished on airway hyperreactivity after O3 exposure of mice sensitized and challenged with Af. O3 stimulated release of pro-neutrophilic mediators including CCL20 and IL-6 into the airways and impaired the inhibitory effects of budesonide on CCL11, IL-13 and IL-23. O3 also prevented budesonide-induced release of the immunoprotective lung collectin SP-D into the airways of allergen-challenged mice. O3 had a bi-phasic direct effect with early (<12 h) inhibition and late (>48 h) activation of SP-D mRNA (sftpd) in vitro. Dexamethasone and budesonide induced sftpd transcription and translation in human type II alveolar epithelial cells in a glucocorticoid receptor and STAT3 (an IL-6 responsive transcription factor) dependent manner. Our study indicates that O3 exposure counteracts the effects of budesonide on airway inflammation, airway hyperreactivity, and SP-D production. We speculate that impairment of SP-D expression may contribute to the acute O3-induced airway inflammation. Asthmatics exposed to high ambient O3 levels may become less responsive to glucocorticoid treatment during acute exacerbations
Deep Task-specific Bottom Representation Network for Multi-Task Recommendation
Neural-based multi-task learning (MTL) has gained significant improvement,
and it has been successfully applied to recommendation system (RS). Recent deep
MTL methods for RS (e.g. MMoE, PLE) focus on designing soft gating-based
parameter-sharing networks that implicitly learn a generalized representation
for each task. However, MTL methods may suffer from performance degeneration
when dealing with conflicting tasks, as negative transfer effects can occur on
the task-shared bottom representation. This can result in a reduced capacity
for MTL methods to capture task-specific characteristics, ultimately impeding
their effectiveness and hindering the ability to generalize well on all tasks.
In this paper, we focus on the bottom representation learning of MTL in RS and
propose the Deep Task-specific Bottom Representation Network (DTRN) to
alleviate the negative transfer problem. DTRN obtains task-specific bottom
representation explicitly by making each task have its own representation
learning network in the bottom representation modeling stage. Specifically, it
extracts the user's interests from multiple types of behavior sequences for
each task through the parameter-efficient hypernetwork. To further obtain the
dedicated representation for each task, DTRN refines the representation of each
feature by employing a SENet-like network for each task. The two proposed
modules can achieve the purpose of getting task-specific bottom representation
to relieve tasks' mutual interference. Moreover, the proposed DTRN is flexible
to combine with existing MTL methods. Experiments on one public dataset and one
industrial dataset demonstrate the effectiveness of the proposed DTRN.Comment: CIKM'2
The effect of lipoprotein-associated phospholipase A2 deficiency on pulmonary allergic responses in Aspergillus fumigatus sensitized mice.
BackgroundLipoprotein-associated phospholipase A2 (Lp-PLA2)/platelet-activating factor acetylhydrolase (PAF-AH) has been implicated in the pathogenesis of cardiovascular disease. A therapeutic targeting of this enzyme was challenged by the concern that increased circulating platelet activating factor (PAF) may predispose to or increase the severity of the allergic airway response. The aim of this study was to investigate whether Lp-PLA2 gene deficiency increases the risk of PAF and IgE-mediated inflammatory responses in vitro and in vivo using mouse models.MethodsLp-PLA2-/- mice were generated and back crossed to the C57BL/6 background. PAF-AH activity was measured using a hydrolysis assay in serum and bronchoalveolar lavage (BAL) samples obtained from mice. Aspergillus fumigatus (Af)-specific serum was prepared for passive allergic sensitization of mice in vivo and mast cells in vitro. β- hexosaminidase release was studied in bone marrow derived mast cells sensitized with Af-specific serum or DNP-IgE and challenged with Af or DNP, respectively. Mice were treated with lipopolysaccharide (LPS) and PAF intratracheally and studied 24 hours later. Mice were sensitized either passively or actively against Af and were studied 48 hours after a single intranasal Af challenge. Airway responsiveness to methacholine, inflammatory cell influx in the lung tissue and BAL, immunoglobulin (ELISA) and cytokine (Luminex) profiles were compared between the wild type (WT) and Lp-PLA2-/- mice.ResultsPAF-AH activity was reduced but not completely abolished in Lp-PLA2-/- serum or by in vitro treatment of serum samples with a high saturating concentration of the selective Lp-PLA2 inhibitor, SB-435495. PAF inhalation significantly enhanced airway inflammation of LPS treated WT and Lp-PLA2-/- mice to a similar extent. Sensitized WT and Lp-PLA2-/- bone-marrow derived mast cells released β-hexosaminidase following stimulation by allergen or IgE crosslinking to equivalent levels. Wild type and Lp-PLA2-/- mice responded to passive or active allergic sensitization by significant IgE production, airway inflammation and hyperresponsiveness after Af challenge. BAL cell influx was not different between these strains while IL-4, IL-5, IL-6 and eotaxin release was attenuated in Lp-PLA2-/- mice. There were no differences in the amount of total IgE levels in the Af sensitized WT and Lp-PLA2-/- mice.ConclusionsWe conclude that Lp-PLA2 deficiency in C57BL/6 mice did not result in a heightened airway inflammation or hyperresponsiveness after PAF/LPS treatment or passive or active allergic sensitization and challenge
Recognition of speed signs in uncertain and dynamic environments
The speed limit signs recognition directly affects the safety of autonomous vehicles. Vehicles are usually running in an uncertain and dynamic environment. The performance of the recognition system is affected by various factors such as the different sizes of pictures, illumination condition and position circumstances, which can lead to misclassification. This makes the speed sign recognition challengeable. To improve the recognition rate of the speed signs in such environments, this work firstly applies the method of the saliency target detection based on the background-absorbing Markov chain, to extract the node in an image, then uses SPP-CNN to classify the extracted nodes with ten-folder validation. The recognition rate is up to 9.32%, higher than that obtained directly by SPP-CNN working on raw dataset
Association study of SNP locus for color related traits in herbaceous peony (Paeonia lactiflora Pall.) using SLAF-seq
Paeonia lactiflora Pall. (P. lactiflora) is a famous ornamental plant with showy and colorful flowers that has been domesticated in China for 4,000 years. However, the genetic basis of phenotypic variation and genealogical relationships in P. lactiflora population is poorly understood due to limited genetic information, which brings about bottlenecks in the application of effective and efficient breeding strategies. Understanding the genetic basis of color-related traits is essential for improving flower color by marker-assisted selection (MAS). In this study, a high throughput sequencing of 99 diploid P. lactiflora accessions via specific-locus amplified fragment sequencing (SLAF-seq) technology was performed. In total, 4,383,645 SLAF tags were developed from 99 P. lactiflora accessions with an average sequencing depth of 20.81 for each SLAF tag. A total of 2,954,574 single nucleotide polymorphisms (SNPs) were identified from all SLAF tags. The population structure and phylogenetic analysis showed that P. lactiflora population used in this study could be divided into six divergent groups. Through association study using Mixed linear model (MLM), we further identified 40 SNPs that were significantly positively associated with petal color. Moreover, a derived cleaved amplified polymorphism (dCAPS) marker that was designed based on the SLAF tag 270512F co-segregated with flower colors in P. lactiflora population. Taken together, our results provide valuable insights into the application of MAS in P. lactiflora breeding programs
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